I've finally started building my computerised, automated pico brewery, 4 years after building the Brewtroller. I've set up a new site for it over at BaldBrewery.com to document the build, list recipes and in future, enable people to follow brews real time.

While CATaLOG was a success most of the time, the most unreliable bit of the system was detecting the RFID tag as the cat went through the door. The system has been offline since June 2010 and we also changed our priorities from tracking the cats in and out to making sure they were safe at night. We purchased a PetPorte RFID catflap which not only reads the cat's embedded microchip reliably, but also imposes access control and has a light sensor so when it gets dark it will only let the cats in, not out.

PetPorte was a UK company and were planning to release a 'computer connection kit' until they were bought by Staywell, when all progress on that front ceased. Upon inspecting the PCB there are headers for additional antenna, programming and serial, so I hooked up a Bus Pirate to see if anything was happening. Nothing was but it seemed I was not alone in my quest. Through emails sent by forum members it transpired PetPorte had signed a 3 year NDA with Staywell and couldn't give us any info on how to make the catflap talk to anything. Yet. So we resigned to waiting until the NDA expired and going from there.

It appears someone couldn't wait this long however and released his own complete rewrite of the firmware. Not able to read the code out of the PIC he just reimplemented the whole firmware from scratch, including decoding the RFID signals from the OP amp into the PIC(!) He also added functionality to determine which way the door is opening via a potentiometer attached to the flap.

I purchased a PICkit 2 programmer, made a lead up and set about reprogramming the catflap. Here it is in action:

This went well and after reassembling the catflap and programming in a test tag I hooked up my TTL-USB converter to the serial header, scanned the tag a few times, entered some control characters and saw this:

Hurrah! All I need to do now is hook the catflap up to a bifferboard, use the same python script controlling the chicken coop to get it on the internet and CATaLOG should be back online soon!

I finally got around to attaching my I-gotu GPS tracker to Tuffin to see where he goes. I cleared the device, charged it and attached it to his harness, ending up with a setup like this.

He didn't like it to start with - it's the same colour as his fur and he kept licking it as he thought it was his own body. Still, the battery was charged, the cat ready so I put some black tape over the GPS receiver and let him go.

He got stuck heading out of the cat flap as he left due to the tracker adding an extra 20mm to his height but after trying again he made it through. After a nervous wait he returned an hour or so later, with the GPS tracker intact, power light still on.

Eagerly we plugged the tracker in and dumped the data - waypoints appeared - woohoo!

It was logging data every 6 seconds and there are 3 erroneous readings from looking at the map, but you can still see he visits the back of around 9 houses, sits on sheds and uses the alleyway in between the rows of houses.

Next
time we will attach it to his collar so it remains facing the sky, and set the logging to every 2 seconds to see if we get better results so stay tuned for updates. Still an amazing insight into our cat's life :D